Degreasing apparatus



July 28, M, RANDALL ET AL DEGREASING APPARATUS Filed Aug. '7, 1957 {A /41m; %X ff/wma, Mfr/N MM 4,

United States Patent DEGREASING APPARATUS Max Randall, Spring Valley, N.Y., and Martin Randall, Bergenfield, N.J., assignors to Ramco Equipment Corp., New York, N.Y., a corporation of New York Application August 7, 1957, Serial No. 676,896

4 Claims. (Cl. 134-57) The present invention relates to improvements in degreasing machines for cleaning metal articles and other objects made of hard, non-absorbent materials, and more particularly to the type employing liquid solvents and their vapors as the principal cleansing agents.

A degreasing machine of this class comprises usually a main tank structure having a plurality of lower tank compartments, one behind the other therein. These tank compartments hold volatile liquid to predetermined levels therein respectively, which are grease solvents and so are their vapors. It is common to use trichlorethylene or perchlorethylene for such purpose. The liquid in the forward tank compartment is kept warm to serve as a bath into which the articles to be cleaned are submerged to soak and then withdrawn. The liquid in the hind tank compartment is subjected to heat to cause its vaporization. Suitable means replenish the liquid supply to such hind tank compartment and withdraw, clean and replenish the liquid supply to the forward tank compartment. Various cleaning sprays and agitating means may be within or interposed between said compartments or suitably positioned in the main tank to act on the work being cleaned and the cleaning liquid. In operation, in such machines heretofore, the upper portion of the main tank is vapor filled. There is a conveyor system to move the work from station to station and thence out of the machine after the work has been washed and subjected to the cleaning and drying action of the vapor.

In such machines as heretofore constituted, the articles to be cleaned were subjected to the action of the vapor before reaching the immersion bath. This I have found to be objectionable because the grit of polishing substances and drawing compounds, the lint of the buffing wheel, the oil and other dirt particles on the articles to be cleaned, became caked and clung tighter onto the work. I have found that when the initial passage of the work through the vapor is omitted and the articles are first subjected to immersion into the cleaning liquid, that their cleansing is quicker because it is easier due to the avoidance of said caking occurrence mentioned.

It is therefore an object of this invention to provide a novel and improved degreasing machine of the character described, in which the articles to be treated are first subjected to immersion in cleaning liquid before entering the vapor zone.

Another object thereof is to provide a novel and improved degreasing apparatus of the class described, in which the work is passed directly into a liquid bath in which it is immersed and then leaves such bath into the vapor zone by providing a vapor seal between the entrance and exit of such bath, which confines the vapor zone to be away from such entrance.

A further object is to provide means to signal the operator if such seal is undone so that he could correct such condition, and also a means to halt the vapor reaching bath entrance in such instance. If desired, a heat cut-01f means may be operated simultaneously with the signal.

' main tank structure.

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Another object is to minimize vapor loss and avoid turbulence in the machine, thus effecting placid operation and economy.

Another object thereof is to provide a novel and improved degreasing machine of the kind set forth, which is easy to maintain and operate, whose cost is within the range of heretofore existing machinery of this class and which is efficient in carrying out the functions for which it is designed.

Other objects and advantages will become apparent as this disclosure proceeds.

For the practice of this invention, one form it may assume comprises a main tank structure, divided in a predetermined number of tank compartments, one behind the other, but of a height which is lower than the The hind tank compartment carries a supply of cleaning liquid and heating means is provided to generate vapor thereof. The most forward tank compartment also holds cleaning liquid kept warm. The main tank structure is provided with a ceiling which extends from the forward wall of the hind tank compartment to about the middle of the most forward tank compartment. There is an exit flue over the hind tank compartment and there is a wall which is a partition in the main tank structure and extends downwardly from the ceiling into the most forward tank compartment, to extend a bit below the level of the liquid therein. Such downwardly extending wall serves to seal the vapor behind it, from the entrance to the main tank structure which is formed, to the most forward tank compartment. Such entrance is also a flue structure and is above the forward half of the most forward tank compartment, which compartment serves as the initial bath into which the work is immersed and then transported rearwardly past the under-edge of said vapor seal wall and thence into the vapor zone.

Passage of the work through the machine and back to operators position is accomplished by suitable running conveyor means. Ultra-sonic means may be positioned within the submersion tank compartment to cause agitation of the liquid therein and spray means are positioned within the vapor zone to further wash the work as it passes them in its travel to be finally acted on by the cleaning and drying action of the vapor as will be explained.

Also provided are means to signal the operator and cut off heat supply to the vapor generator if the level of the liquid in the submerging tank compartment should fall to a point where the seal would be or is undone and means which would maintain a low vapor level at the entrance to the tank structure, if such seal is undone.

In the accompanying drawings forming part of this specification, similar characters of reference indicate corresponding parts in all the views.

Fig. 1 is a central vertical longitudinal section shown partly diagrammatic, of a degreasing machine embodying the teachings of this invention.

Fig. 2 is the left end view thereof, shown however as a section taken at lines 22 in Fig. 1.

Fig. 3 is a fragmentary view which is part of Fig. 1 showing the signal means and the electrical circuit for operating same and the heat cut-off.

In the drawing which shows one form this invention may assume, the numeral 15 designates generally a main tank structure having side walls 16, 17, a front wall 18, a relatively higher rear wall 19 and a floor wall 2t), 24). The comparatively low, spaced partitions 21 and 22, extending from the floor, form the tank compartments 23, 24, 25, one behind the other; the front of the apparatus being at the left in Fig. 1. At about the top edge level of the front wall 18, the main tank structure is provided with a ceiling 26 which extends from above the middle of the tank compartment 23 to the plane of the rear partition 22. Extending downwardly from the forward end of the ceiling and part way down into the tank compartment 23, there is a partition wall 27. Extending upwardly from the rear end of the ceiling, is the partition wall 28. The main tank structure is thus provided with the entrance 29 downwardly thereinto at its front end and the exit 30 outwardly from the top thereof at its rear end.

A suitable conveyor system indicated generally by the numeral 31, is installed as shown to bring basket 32 containing the work, first down into the tank compartment 23 and down therein to be submerged in warm degreasing liquid 33 below the level of the underedge of the partition 27 which extends part way into such liquid and thence rearwardly past such partition and then upwardly into the vapor zone 34 behind such partition 27, where the work passes degreasing liquid sprays issuing from pairs of spray nozzles 35 and 36. Then the work moves rearward in the vapor zone directly above the rear tank compartment 25 which serves as the vapor generator; the clean liquid supply 37 in such tank compartment 25 being subjected to suflicient heat by means 52, to vaporize same. The work finally emerges out of the exit 30 thoroughly cleaned and dried and is returned at the front of the apparatus to operators position for removal.

As is usual in this type of machine, the exit flue 30 as it may be called, has the condenser 38 to limit the vapor level therein, but in the embodiment shown, the entrance flue 29 is also provided with the condenser 39 to limit the vapor level therein should the vapor seal effected at the entrance to the duct 50 be undone, which would happen if the liquid level in the tank compartment 23 should fall below the underedge of the partition 27. Since the existence of such vapor seal is important for the practice of this invention, because it is the means which keeps the work from coming in contact with vapor before it receives an immersion bath in the degreasing liquid in the tank compartment 23, some sort of indicating or preferably a signal means is provided to apprize the operator when the seal is broken so he may correct it by raising the level of the degreasing liquid 33 to be above the underedge of the partition 27. For this signalling purpose, there may be an electrical circuit indicated generally by the numeral 40 which comprises the bell 41, batteries 42 and a switch 51 whose operating member is a float 43 which is controlled by the level of the liquid 33. This switch device may also serve to cut off the current supply to the heating means 52 used for vapor generation.

The conveyor means shown, consists of a pair of spaced endless chains or belts 45, 45', constantly moving on a system of properly positioned sprockets or pulleys. Suitably spaced horizontal bars 44 span the chains and detachably swingably support perforated baskets as 32 into which the articles to be cleaned are placed for transportation through the machine. The point of discharge of the finished cleaned work may be other than at the operators position at the front of the machine.

Machines of this class are of course provided with degreasing liquid supply means, pumping, filtering, purifying and replenishment feed systems and with the required heating means for the submersion bath and the vapor generator as well as coolant for the condenser means. These appurtenances are not shown in the drawing, because they are well known as to structure and use by those versed in this art and therefore need no further illustration or explanation. If desired, ultra-sonic, as for instance a magnetostrictive or other suitable agitating means 46, may be employed within the tank compartment 23.

For the operation of this machine to attain the benefits of this invention, the level of the degreasing liquid 33 in tank compartment 23 is originally made to be and is maintained so that the underedge of the partition member 27 is within the liquid. As mentioned, should such liquid level fall to clear such partition, the signal bell 41 would become actuated to notify the operator to correct such objectionable condition, and until he does so, the vapor level in front of the partition 27, is restricted at and by the condenser means 39, thus avoiding the loss of cleaning material and preventing its escape and consequent contamination of the surrounding atmosphere.

The foregoing description is of the preferred embodiment illustrated in the drawing. However, the general scheme of this invention may be said to comprise a tank 23 filled to above a certain level with a degreasing liquid to serve as a soaking bath and a container 34 having vapor of degreasing liquid therein; said container having a duct or other communicative passage leading therefrom into said tank so that the opening of said duct within the tank is downwardly therein and at a level below that of the liquid in such tank to effect a liquid seal to block the gaseous cleaning vapor. Said container has an exit opening 30 and contemplates that said container may be open on top with suitable sized cooling means 38 thereabout to maintain vapor level. In such instance such open top would be the exit opening. Also, there is the conveyor system as for instance 31 to transport articles to be cleaned over the course, namely from the outside air into the liquid in the tank, then up through said duct into the vapor within the container and thence out of such container to any suitable place where the cleaned work is taken off the conveyor by an operator or by automatic means. Also as indicated there may be the various other appurtenances to limit vapor level, to signal the operator and to cut off the heat as mentioned. In the specific construction illustrated, the partitions 21 and 27 which are crosswise of the main tank structure, may be referred to as the first and second partitions respectively. This resum is stated as an aid in defining the structure set forth in the appended claims.

Of importance to note, is that in the machine taught herein, there is only one air-vapor interface, thus minimizing the area of diffusion of vapor into the air. This of course holds down vapor loss to a minimum and operating costs are substantially reduced. Also, the controlled depressed vapor level effected at the entrance to the initial soaking tank upon the breaking of the seal, stabilizes the vapor contents of the machine against any turbulence which might be created by drafts or otherwise, thus creating a placid condition of vapor level and occasioning a minimum of vapor loss due to disturbances of the air-vapor interface.

This invention is capable of numerous forms and various applications without departing from the essential features herein disclosed. It is therefore intended and desired that the embodiment shown herein shall be deemed illustrative and not restrictive and that the patent shall cover all patentable novelty herein set forth; reference being had to the following claims rather than to the specific description herein to indicate the scope of this invention.

We claim:

1. In a degreasing apparatus of the character described, the combination of a tank for holding degreasing liquid, a container for receiving a supply of degreasing vapor, a degreasing vapor generating means arranged to supply such vapor into said container; said generating means including a heating means adapted to vaporize a supply of degreasing liquid, a duct leading from said vapor container into the tank and opening downwardly therein at a level below that of the liquid in said tank whereby the lower portion of said duct is filled with liquid thereby effecting a seal to block the vapor; said container having an exit opening, cooling means at the upper portion of the tank above the liquid level for maintaining the vapor at a predetermined level there when the level of the liquid in said tank falls below the opening of the duct which is in said tank, a conveyor system arranged to transport work to be cleaned, first down into the liquid in the tank, then upwardly through said duct and thence into the vapor in said container and then out of said vapor container through said exit opening and means for deactuating said heating means, controlled by the level of the liquid in the tank and arranged to operate when said level falls to a predetermined position.

2. The apparatus as defined in claim 1, wherein the heater deactuating means is arranged to operate when the level of the liquid in the tank falls below the opening of the duct which is Within said tank.

3. In a degreasing apparatus of the character described, a main tank structure comprising front, rear, side, floor and ceiling walls, a first partition crosswise within said structure extending upwardly from the floor wall; the upper edge of said partition being spaced from the ceiling wall whereby a tank compartment is formed in the forward region of said structure, a second partition crosswise within said structure and extending downwardly from the ceiling wall into the said forward tank compartment; said partions being spaced; there being an entrance opening into the forward tank compartment forwardly of the second partition and an exit opening from the main tank structure rearwardly of the second partition, a vapor generating means to vaporize degreasing liquid Within the tank structure rearward of the second partition; the forward tank compartment serving to hold degreasing liquid to a level above the underedge of the second partition thereby effecting a seal to block the vapor, a conveyor system carried on the main tank structure, arranged to transport work to be cleaned, first to said entrance opening and into the liquid in the forward tank compartment, then across the underedge of the second partition and thence upwardly out of said compartment into that portion of the structure which is rearwardly of the second partition and thence out through said exit opening and a means for deactuating the vapor generator, controlled by the level of the liquid in the forward tank compartment and arranged to operate when said level falls to a predetermined position.

4. The apparatus as defined in claim 3, wherein the deactuating means is arranged to operate when said level falls below the underedge of the second partition.

References Cited in the file of this patent UNITED STATES PATENTS 

